Management of Vitamin D Deficiency

Vitamin D is a steroid hormone classically involved in the calcium metabolism and bone homeostasis. Vitamin D is produced by skin exposed to ultraviolet B radiation or obtained from dietary sources, including supplements. Vitamin D Deficiency is the most common nutritional deficiency worldwide, characterized by serum 25-hydroxyvitamin D <20 nanograms/mL. Vitamin D insufficiency is regarded as a serum 25-hydroxyvitamin D level between 21-29 nanograms/mL. The causes for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or impaired intestinal absorption .The other causes of D deficiency might be inherited disorders that either reduce or prevent the metabolism of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D, these disorders are present with biochemical and skeletal abnormalities, but in a more severe form. Most patients are asymptomatic. Severe prolonged vitamin D deficiency causes growth retardation and rickets in children and osteomalacia, osteopenia, and osteoporosis in adults. Moreover, in the last decades, several extra skeletal effects which can be attributed to vitamin D have been shown. These beneficial effects will be here summarized, Both vitamin D deficiency and vitamin D insufficiency are corrected by giving vitamin D2 or vitamin D3 in treatment doses followed by lifelong maintenance doses; adequate, sensible sunlight exposure should be encouraged. This review outlines strategies to prevent, diagnose, and treat vitamin D deficiency in adults and children.